A Radon and Hough transform searches through an image for evidence of edges/ridges by taking the integral over a line passing through the image (e.g., for 2D). By testing many different lines through the image, the methods find which, if any, imaginary line has the strongest support by comparing integrals. A method of edge detection that uses a Radon transform may take the integral, e.g., sum of values, along “all possible lines,” and reports the maximum sum of values.